1. Field of the Invention
The present invention relates to a switch device for use in a timepiece such as a wristwatch, and a timepiece including the switch device.
2. Description of the Related Art
For example, a wristwatch is known which includes a switch device where an operating member such as a crown has been provided in a wristwatch case such that it can be pulled outward, as described in Japanese Patent Application Laid-Open (Kokai) Publication No. 2006-194834.
This type of switch device is structured such that the time can be adjusted by the operating member, which is protruding from the wristwatch case, being pulled outward and rotated in this state.
In this structure of the switch device, a winding stem pipe is fitted into a through hole of the wristwatch case, a shaft section of the operating member is inserted into the winding stem pipe, and the outer end of a winding stem is mounted on the shaft section of the operating member, whereby the winding stem slides and rotates in accordance with the operation of the outer end of the operating member.
In this case, a ring member having a plurality of engaging projections is mounted on the operating member.
Also, the winding stem pipe has a small-diameter section that is fitted into the through hole of the wristwatch case and a large-diameter section that protrudes outside of the wristwatch case. On the outer circumferential surface of the large-diameter section, a plurality of engaging grooves are provided which engageably lock the engaging projections of the ring member.
These engaging grooves each include a guide groove for attachment and detachment which attachably and detachably guides an engaging projection of the ring member in the axial direction of the winding stem pipe, a lock groove which restricts the movement of the engaging projection of the ring member in the axial direction to lock the engaging projection, and a communication groove which guides the engaging projection of the ring member to one of the guide groove and the lock groove.
As a result, in the switch device, when the operating member is to be locked, the engaging projection of the ring member is inserted and pushed into the guide grove. Then, when the operating member in this state is rotated, the engaging projection of the ring member is moved to the lock groove via the communication groove, whereby the movement thereof in the axial direction of the winding stem pipe is restricted, and the operating member is locked in a state of being pushed in.
Also, in the switch device, when the lock on the operating member is to be released, the operating member is rotated while being pushed inward. As a result, the engaging projection of the ring member positioned in the lock groove is moved from the lock groove to the guide groove via the communication groove, whereby the lock on the engaging projection by the lock groove is released. In this state, when the engaging projection of the ring member is moved in the axial direction to be detached from the guide groove, the operating member is pulled outward, whereby the time can be adjusted.
However, in this switch device, when the lock on the operating member is to be released, the engaging projection of the ring member positioned in the lock groove cannot be detached from the lock groove unless the operating member is rotated while being pushed inward. Therefore, the operability of the operating member is deficient. Also, when the operating member is in the locked state, if the outer end thereof hits some object and is inadvertently rotated, the lock on the operating member is released, which may cause an erroneous operation.